Israel and the United States are discussing the feasibility of curbing Iran's imports of gasoline and other refined oil products if Teheran refuses to enter negotiations over its nuclear program, an Israeli official was reported by Reuters as saying on Monday.

American officials refused to say whether they were considering such a move, which would represent an escalation of existing sanctions against the Islamic republic and hit the average Iranian in the pocket.

The Israeli official, however, speaking on condition of anonymity, said a possible gasoline import ban "has been discussed for a long time" between the allies, but that policymakers in Washington were concerned Teheran's response could have implications for global oil markets.

Iran has threatened to retaliate against a cutoff of its gasoline imports by stopping its crude oil exports to Western countries. The country could also disrupt oil tanker traffic through the Strait of Hormuz. About 17 million barrels of oil a day pass through the strait.

US President Barack Obama has given Teheran a deadline of September to agree to international talks about its uranium enrichment program. Israel and Western powers fear Iran is pursuing nuclear weapons while the country insists the program is intended to generate electricity.

Iran has the world's third largest proven oil reserves but still imports 40 percent of its gasoline to meet growing demand because of limited refining capacity.

The White House and State Department on Monday would not comment on whether a gasoline import ban was an option under discussion with Israel and European allies.

"With respect to the potential actions that might be undertaken by the international community [against Iran], we're not going to be commenting on what might or might not be done," said US Secretary of State Hillary Clinton.

"So we're not prepared to talk about any specific steps. But I have said repeatedly, in the absence of some positive response from the Iranian government, the international community will consult about next steps and certainly next steps can include certain sanctions," she added.

White House spokesman Robert Gibbs said the United States would consult with its allies in September. "But I don't want to get into discussions amongst allies or hypotheticals as we get toward those dates," Gibbs told reporters on Monday.